3: Case Gasoline
Hay for the Horseless Carriage
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What changes in transportation?
3500 BC 1000 BC 700 BC 500 BC 300 BC 800 AD 1100 AD 1580 D Gilgamesh Old Testament Iliad, Odyssey Shih Ching Mahabharata Beowulf Song of Roland Shakespeare
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Average Family Spending, 1992
tax 9% insurance 16% food 13%
misc 6% entertain 4% health 5% transport 15%
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house 27%
clothes 5%
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Need for Transportation
Promote political unity and military need
Egypt and Nile river Roman roads, move legions to provinces English railroad, troops to Ireland
Promote general welfare
commerce and trade (necessity) tourism and vacation (luxury)
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Social Effects
Separation of places of work from places of residence
move to suburbs, 40 mile commute
Movement of industry out of center city
outlying industrial parks CBD for finance, government, culture, recreation
Movement of farm produce to market
fresh milk, vegetable, fruit
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Egypt (linear) A C
France (hub)
P
S
B A T
L
M
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von Thunen Theory
livestock milk,vegetable grain City
river
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farming single residence
multi-residence
major road, commerce
transition CBD
Detroit
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Population Density
City Manhattan New York San Fran Chicago Los Angel Houston
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Pop, mil 1,488 7,323 724 2,784 3,485 1,631
Pop/sq mile 52,400 23,700 15,500 12,250 7,420 3,020
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Area, sq mile 28.4 309.0 46.7 227.2 469.3 539.9
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The Need for Car and Gasoline
Transportation of people and goods Travel from any point to any other point via dense network of local roads (compared to trains on fixed lines) Cheap enough for mass consumption Personal liberty of schedule, and freedom to live far from work
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Events
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1712 1772 1801 1826 1889 1896 1902
Newcomen steam engine James Watt double-acting engine Robert Fulton steamboat Stephenson railroad Daimler-Benz petroleum car Ford mass production Wright Brothers airplane
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The Invention and Inventors
1859 Drake oil drilling, and the rise of modern oil refining Distillation, whisky, 1923 McCabe-Thiele Cracking, 1912 William Burton, 1927 Eugene Houdry, Lewis and Gilliland Octane additive, 1921 Thomas Midgley Reforming, 1950 Valdimir Haensel
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Eugene Houdry
1892 born in Paris 1914 French army 1927 discovered silicaalumina catalyst for cracking 1930 Vacuum Oil, NJ 1936 first commercial production at Marcus Hook, PA 1956 proposed automobile catalytic converter 1962 died Philadelphia
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Requirements for Auto Fuel
High heat of combustion in calorie/gm Liquid in operation and storage, as solid is difficult to feed, and gas needs large volume and pressure Volatile for easy starting in winter, not too volatile or vapor lock in summer Octane number to allow high compression and performance Humongous supply and low cost
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Wood and charcoal Hard and soft coal Whale oil Corn alcohol Wood alcohol Petroleum
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Combustion Heats, kcal/gm
Hydrogen 27.4 Petroleum 10.3 Whale oil 9.5 Cotton seed oil 9.4 Graphite 7.8 Ethyl alcohol 7.1 Illinois Bitumin 6.7 Methyl alcohol 5.3 Oak 4.0
[what are the fuels of transportation in nature?]
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Heat of Combustion
A heat engine works by burning fuel, which heats up a gas mixture, which expands and pushes a cylinder H has high heat per gram, C has low heat, O has no heat of combustion Paraffin > aromatics > alcohol
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heat, kcal/gm
12 10 8 6 4 2 0 1234567891 0 paraffin alcohol
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Components of Petroleum
Saturated paraffins CnH2n+2
n is the number of carbons in the chain, 1-4 are gases, 5-14 are liquids, 15- are solids are room temperature normal-paraffins have straight chains iso-paraffins have branch chains
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Petroleum Cyclo-paraffins Components
CnH2n Aromatics C6H6
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States of Matter
Gas: weak attraction between molecules, free to move and widely separated, in contact only at collision Liquid: medium attraction between molecules, molecules constantly in contact but free to move around Solid: strong attraction between molecules, rigidly bound to neighbors
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Inter-molecular forces and boiling points
Inter-molecular forces hold molecules together in liquid, stronger with larger molecules and polar forces Thermal forces pulls molecules apart, stronger at high temperature
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Small size and nonpolarity leads to low boiling point Large size and polarity leads to high boiling point
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boiling points
350 300 250 200 150 100 50 0 -50 0 -100 -150 -200
b.p. in C
paraffin alcohol 5 10 15 20
carbon number
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Electronegativity and Polarity
Electronegativity
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Na H C S N Cl O F
0.9 2.1 2.5 2.5 3.0 3.0 3.5 4.0
Na+ Cl- 3.0-0.9=2.1 ====> O- = C+ =O3.5-2.5=1.0 O3.5-2.1=1.4 H+ H+ H 2.5-2.1=0.4 H-C- H H
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Influence of molecular shape on boiling point
density m.p. n-octane 2,2,4-tri methyl pentane
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b.p.
H vapo
0.703 -56.8 125.7 86.8 0.692 -107.4 99.2 73.5
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Vapor pressure above liquid
Heat of vapaorization, H, is the difference between the more energetic gas and the more bound liquid The higher the temperature, the more energetic are the molecules, so that more liquid vaporize The Clausius-Clapeyron Equation states that: ln(P/Po) = (H/R)(1/To - 1/T) P is the vapor pressure at temperature T in K Po is the vapor pressure at reference temperature To H is the heat of vaporization, cal/mol R is the gas constant, 1.987 cal/mol.K
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v a p o r p r e ssu r e o f w a t e
800 700 600 mm Hg 500 400 300 200 100 0 0 50 T em p C 100
H=595 cal/gm, Po=760 mmHg at 100C or 373 K
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Separation by Distillation
A liquid mixture with x1 fraction of light, and x2 fraction of heavy component For ideal mixture, Raoults Law states that the partial pressure p1=x1P1 , and p2=x2P2 At 50 C, vapor pressure of pure hexane is 400 mm Hg, and of pure heptane is 140 mm Hg The vapor with y1 fraction of light, which is y1=p1/(p1+p2)
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Equilibrium Curve
1 0.9 0.8 0.7 Gas y1 0.6 0.5 0.4 0.3 0.2 0...